Maintaining deposit-free heat exchange surfaces in water systems, particularly in industrial water systems, e.g., cooling water systems and heating water systems, is important to optimizing energy efficiency. Mineral deposit, particularly calcium salts, and more particularly calcium carbonate, may be in the form of scaling or fouling. Generally, scaling is the precipitation of inorganic salts on equipment surfaces, and fouling results from deposit of insoluble particles suspended in a liquid. Monitoring industrial water systems to minimize or prevent deposit (mineral or otherwise) onto heat exchange surfaces can provide information that can be utilized to improve, or at least maintain, efficiency in an industrial water system's operation and/or treatment program.
Biofilm deposit onto heat exchange surfaces can also cause inefficiency in industrial water systems. For example, compared to mineral deposit, biofilm deposit is generally a 4 to 5 times better insulator than mineral deposit. Generally, biofilms are slimy, and the microorganisms causing the formation of a biofilm may represent merely a small fraction of the biofilm's content.